High Energy Physics - Theory

Title:Relaxation of vacuum energy in q-theory

Abstract: The $q$-theory formalism aims to describe the thermodynamics and dynamics of
the deep quantum vacuum. The thermodynamics leads to an exact cancellation of
the quantum-field zero-point-energies in equilibrium, which partly solves the
main cosmological constant problem. But, with reversible dynamics, the
spatially-flat Friedmann-Robertson-Walker universe asymptotically approaches
the Minkowski vacuum only if the Big Bang already started out in an initial
equilibrium state. Here, we extend $q$-theory by introducing dissipation from
irreversible processes. Neglecting the possible instability of a de-Sitter
vacuum, we obtain different scenarios with either a de-Sitter asymptote or
collapse to a final singularity. The Minkowski asymptote still requires
fine-tuning of the initial conditions. This suggests that, within the
$q$-theory approach, the decay of the de-Sitter vacuum is a necessary condition
for the dynamical solution of the cosmological constant problem.